<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>有小陆真是太好啦</title>
    <style>
        body {
            background-color: black;
            text-align: center;
            margin-top: 100px;
        }

        div {
            color: red;
            font-size: 150px;
        }

        p {
            display: none;
            color: red;
            font-size: 100px;
        }

        img {
            display: none;
        }
    </style>
</head>
<body>
<img id="icon" src="http://upfile.asqql.com/2009pasdfasdfic2009s305985-ts/2014-9/201492322593567156.gif">
<p id="word">圣诞节快乐</p>
<div id="number">3</div>

<script>
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    var p = document.getElementById('word');
    var number = document.getElementById('number');

    var timer = setInterval(function () {
        number.innerText -= 1;

        if (number.innerText <= 0) {
            clearInterval(this.timer);

            p.style.display = 'block';
            img.style.display = 'inline-block';
            number.style.display = 'none';
            document.body.style.backgroundColor = 'white';
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    }, 1000);
</script>
</body>
</html>